Not Applicable
1. Field of the Invention
This invention relates generally to sensors utilizing electromagnetic energy for detecting the passage of substances through a chamber, and more particularly to such sensors in which said electromagnetic energy is non-resonant.
2. Description of the Related Art
Sensors which use electromagnetic energy for detecting the passage of a substance through a chamber are well known in the art and have found applications in a number of industries. For example, in the agricultural industry, electromagnetic sensors have been used for monitoring seed planting operations as disclosed in U.S. Pat. No. 4,246,469 to Merlo, and for monitoring crop moisture as disclosed in U.S. Pat. No. 5,708,366 to Nelson. In the petroleum industry, sensors using electromagnetic energy have been used for determining solid-to-liquid ratios in a flowing petroleum stream as disclosed in U.S. Pat. No. 5,644,244 to Marrelli et al.
Unfortunately, the inventions disclosed in these patents fail to solve the need of providing a single sensor that can be used for detecting the presence, flow-rate, and/or volume of various substances, whether the substance being measured is a solid, a liquid, or a gaseous material such that only one sensor is needed for all the monitoring needs of a user. Nor do these sensors provide for both quantitative and qualitative detection of substances. Thus, those concerned with these and other deficiencies recognize the need for an improved electromagnetic energy sensor.
A non-resonant electromagnetic energy sensor which generates output signals upon the quantitative and/or qualitative detection of the flow of various analyte substances including solid particles flowing as discrete individual particles or as a continuum, as well as the flow of liquids and/or gaseous analyte substances. The non-resonant electromagnetic energy sensor may be electronically interfaced with various types of electronic circuitry whereby the generated output signals may be used for monitoring a variety of flowing substances, for example, seed flow in an agricultural planter, crop yield on a combine harvester, and flow rates of liquids or gaseous fluids under pressure.
The sensor comprises a housing having wall members defining a chamber having an interior volume. The sensor is designed to be interposed along a length of conduit through which the analyte will pass. An electromagnetic energy source and an electromagnetic energy detector are in communication with the interior volume of the chamber. The electromagnetic energy source propagates non-resonant electromagnetic energy of a predetermined frequency and amplitude into a measuring region within the interior volume of the chamber. The electromagnetic energy detector detects the signal variations of the electromagnetic energy within the measuring region caused by the perturbation of the electromagnetic energy field due to the passage of the analyte therethrough and responds to these signal variations by generating output signals. By interfacing various types of electronic circuitry to receive these output signals, the non-resonant electromagnetic energy sensor may be used to quantitatively and/or qualitatively detect the analyte, whether the analyte is a solid flowing as discrete particles or as a continuum, or whether the analyte is a flowing liquid, or flowing gaseous substance.
Other objects, advantages, and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.